1. Field of the Invention
Exemplary aspects of the present invention generally relate to an image forming apparatus, such as a copier, a facsimile machine, or a printer, and more particularly, to an image forming apparatus that transports developer using a flow of air, and a method for developing a latent image on an image bearing member with developer.
2. Description of the Background Art
In general, image forming apparatuses, such as printers, facsimile machines, and copiers, that form an image using an image bearing member, are equipped with a developing device to develop a latent image on the image bearing member with a developer, examples of which are disclosed in Japanese Patent Unexamined Application Publication No. Hei08-123199, Japanese Patent No. 3349286, and Japanese Patent No. 3391926.
However, in such a related art developing device, a rise in temperature of the developer may cause characteristics of the developer to change, in particular causing reduction in its fluidity and developability, and accumulation of developer particles and so forth that ultimately leading to deterioration of imaging quality.
Generally, the temperature of the developer in the developing device is most likely to rise due to frictional heat generated during agitation of the developer, contact of the developer with other components, and/or eddy current generated when a developing sleeve rotates around a magnet at a relatively high speed.
Further, a light source, a fixing device, and other components, including a motor, for example, generate heat in the image forming apparatus, also causing the temperature of the developer to rise.
This problem of heat generation and its effects on the characteristics of the developer are particularly acute in the case of methods for transporting the developer involves using a flow of air (hereinafter “airflow). For example, Japanese Patent Unexamined Application Publication No. Hei08-123199 discloses a developing device that transports a developer using airflow. When transporting the developer using airflow as disclosed in the related art, air is circulated in the image forming apparatus so as to facilitate transport of the developer.
According to this related-art approach, with a relatively simple structure it is possible to transport the developer to relatively distant locations through selectable paths.
However, a drawback to this technique is that the light source, the fixing device, and other heat-generating components including the motor cause undesirable heating of the air being circulated, thus raising the temperature of the developer transported by airflow.